<?php
function smart_resize_image($file,
                            $dataString = null,
                            $width = 0,
                            $height = 0,
                            $proportional = false,
                            $output = 'file',
                            $delete_original = true,
                            $use_linux_commands = false,
                            $quality = 100,
                            $dest = ''
)
{
    if ($height <= 0 && $width <= 0) return false;
    if ($file === null && $dataString === null) return false;

    # Setting defaults and meta
    $info = $file !== null ? getimagesize($file) : getimagesizefromstring($dataString);
    $image = '';
    $final_width = 0;
    $final_height = 0;
    list($width_old, $height_old) = $info;
    $cropHeight = $cropWidth = 0;

    # Calculating proportionality
    if ($proportional) {
        if ($width == 0) $factor = $height / $height_old;
        elseif ($height == 0) $factor = $width / $width_old;
        else                    $factor = min($width / $width_old, $height / $height_old);

        $final_width = round($width_old * $factor);
        $final_height = round($height_old * $factor);
    } else {
        $final_width = ($width <= 0) ? $width_old : $width;
        $final_height = ($height <= 0) ? $height_old : $height;
        $widthX = $width_old / $width;
        $heightX = $height_old / $height;

        $x = min($widthX, $heightX);
        $cropWidth = ($width_old - $width * $x) / 2;
        $cropHeight = ($height_old - $height * $x) / 2;
    }

    # Loading image to memory according to type
    switch ($info[2]) {
        case IMAGETYPE_JPEG:
            $file !== null ? $image = imagecreatefromjpeg($file) : $image = imagecreatefromstring($dataString);
            break;
        case IMAGETYPE_GIF:
            $file !== null ? $image = imagecreatefromgif($file) : $image = imagecreatefromstring($dataString);
            break;
        case IMAGETYPE_PNG:
            $file !== null ? $image = imagecreatefrompng($file) : $image = imagecreatefromstring($dataString);
            break;
        default:
            return false;
    }


    # This is the resizing/resampling/transparency-preserving magic
    $image_resized = imagecreatetruecolor($final_width, $final_height);
    if (($info[2] == IMAGETYPE_GIF) || ($info[2] == IMAGETYPE_PNG)) {
        $transparency = imagecolortransparent($image);
        $palletsize = imagecolorstotal($image);

        if ($transparency >= 0 && $transparency < $palletsize) {
            $transparent_color = imagecolorsforindex($image, $transparency);
            $transparency = imagecolorallocate($image_resized, $transparent_color['red'], $transparent_color['green'], $transparent_color['blue']);
            imagefill($image_resized, 0, 0, $transparency);
            imagecolortransparent($image_resized, $transparency);
        } elseif ($info[2] == IMAGETYPE_PNG) {
            imagealphablending($image_resized, false);
            $color = imagecolorallocatealpha($image_resized, 0, 0, 0, 127);
            imagefill($image_resized, 0, 0, $color);
            imagesavealpha($image_resized, true);
        }
    }
    imagecopyresampled($image_resized, $image, 0, 0, $cropWidth, $cropHeight, $final_width, $final_height, $width_old - 2 * $cropWidth, $height_old - 2 * $cropHeight);


    # Taking care of original, if needed
    if ($delete_original) {
        if ($use_linux_commands) exec('rm ' . $file);
        else @unlink($file);
    }

    # Preparing a method of providing result
    switch (strtolower($output)) {
        case 'browser':
            $mime = image_type_to_mime_type($info[2]);
            header("Content-type: $mime");
            $output = NULL;
            break;
        case 'file':
            $output = $file;
            break;
        case 'return':
            return $image_resized;
            break;
        case 'newimage':
            $output = $dest;
            break;
        default:
            break;
    }


    # Writing image according to type to the output destination and image quality
    switch ($info[2]) {
        case IMAGETYPE_GIF:
            imagegif($image_resized, $output);
            break;
        case IMAGETYPE_JPEG:
            imagejpeg($image_resized, $output, $quality);
            break;
        case IMAGETYPE_PNG:
            $quality = 9 - (int)((0.9 * $quality) / 10.0);
            imagepng($image_resized, $output, $quality);
            break;
        default:
            return false;
    }

    return true;
}

?>